158 



of the small changes of level in the cistern j and being well 

 accustomed to barometric measurements, employed every ne- 

 cessary precaution, to obtain an accurate result. The fol- 

 lowing is the table of his observations. 



TABLE. 



Stations. 



Hours. 



Barometer. 



Reaum. 

 Therm. 



Estancia de los Ingleses 

 Port of Orotava 



k 



inch, lines. 

 19 9*5 



28 4 6 



4'9o 

 150 



Summit of the Peak 

 Port of Orotava 



the morning 



18 40 



28 56 



67 

 19-9 



The corresponding barometer was placed at the height of 

 seven toises above the level of the sea. Mr. Cordier found 

 by Deluc's formula the Station of the Rocks to be 1529 

 toises, and the top of the volcano 1901 toises. Mr. Laplace's 

 formula gave me for the first of these points 1550 toises ; and 

 1920 toises* for the second. 



been communicated to me by Mr. Cordier. This traveller, 

 who has visited Egypt, Spain, and the Canary Islands, is 

 preparing an interesting work on extinct volcanoes. 



* In the manuscript voyage of Mr. O'Donnell, for the 

 communication of which I am indebted to the kindness of 

 Mr. Leude" de Segrai, is the following note : " The barome- 

 tric measurements which we made of the height of the vol- 

 cano nearly coincide (con corta differ encid) with those of 

 Mr. Cordier, paying attention to the difference between the 

 French and Spanish toises, absolute height of the ravines at 

 the foot of the Peak 1278 Spanish toises ; Estancia de los 



